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You may have a family member who has viral hepatitis. Or perhaps you recently saw a news brief about a celebrity who contracted hepatitis A or B. Whatever the reason, you want information about a viral illness that you may not have thought much about. What is viral hepatitis? Are you at risk for it? Do you need viral hepatitis vaccines?

Hepatitis A and B: Diseases of the Liver

Hepatitis is an inflammation of the liver, most often caused by a viral infection. There are three common types of hepatitis caused by viruses: hepatitis A, hepatitis B, and hepatitis C. Vaccines have been developed that protect people from contracting hepatitis A and B. There is no vaccine for hepatitis C.

Hepatitis A and hepatitis B can be spread from person to person, although in different ways. They have similar symptoms, which include abdominal pain, fever, fatigue, joint pain, and jaundice (yellowing of the skin and whites of the eyes).

Over the last 20 years, there has been a 90% decrease in cases of hepatitis A and an 80% decrease in hepatitis B cases in the U.S. Health experts believe that immunization efforts have led to this drop in rates of infection.

How Hepatitis Is Spread

Hepatitis A: About 20,000 people in the U.S. contract hepatitis A each year. The hepatitis A virus is found in the stool of the infected person. It is spread through contaminated food or water or by certain types of sexual contact.

Children who get hepatitis A often don't have symptoms, so they can have the virus and not know it. However, they can still spread it easily. Fortunately, children are now routinely vaccinated against hepatitis A.

Most people who get hepatitis A recover completely within two weeks to six months and don't have any liver damage. In rare cases, hepatitis A can cause liver failure and even death in older adults or people with underlying liver disease.

Hepatitis B: Every year, about 40,000 people in the U.S. become infected with hepatitis B. Acute hepatitis lasts from a few weeks to several months. Many infected people are able to clear the virus and remain virus-free after the acute stage. However, for others, the virus remains in the body, and they develop chronic hepatitis B infection, which is a serious, lifelong condition. About 1.2 million people in the U.S. have chronic hepatitis B. Of these, 15% to 25% will develop more serious health problems, such as liver damage, cirrhosis, liver failure, and liver cancer, and some people die as a result of hepatitis B-related disease.

Hepatitis B can be spread from one person to another from the blood, semen, or other body fluids of an infected person. In the U.S., sexual contact is the most common way that hepatitis B is spread. It can also be spread by sharing needles or other equipment used to inject drugs. In addition, a mother can pass hepatitis B to her baby during birth.

Hepatitis B cannot be spread by contaminated water, food, cooking, or eating utensils, or by breastfeeding, coughing, sneezing, or close contact such as kissing and hugging.

Vaccines for Hepatitis A and B

Our immune system battles foreign invaders every day, such as when we get a cold virus. When this happens, we develop immunity to that specific virus. This means that our body will fight off the virus if it is ever exposed to it again.

The same protection happens with vaccines. However, the benefit of a vaccination is that you don't have to go through being sick to enable your body to fight off disease.

Gregory Poland, MD, director of the Mayo Clinic's Vaccine Research Group, explains that hepatitis vaccinations contain a small amount of the inactive virus. When you get a dose of the vaccine, he says, your immune cells respond by developing immunity against the virus. This immunity lasts over a long period of time.

"So if I get these two doses of hepatitis A vaccine, and then I get exposed 30 years from now, my body will remember that immunity to the vaccine and rapidly start producing antibodies again," says Poland.

Due to the way hepatitis vaccinations are developed, it is impossible to contract the virus from the vaccine itself, according to Poland.

The hepatitis A vaccine is usually given in two shots and the hepatitis B vaccine is administered as a series of three shots. The most common side effects are redness, pain, and tenderness where the shots are given.

To get long-term protection from these viruses, it's important to receive all the shots as scheduled. However, if you received one shot and never went back for the others, it's not too late to catch up.

"No matter how long the lapse is between doses, you never have to start the series again," says Poland. "You just take off where you left off. So even if someone got their first dose five years ago, we start with the second dose."

Who Should Get Hepatitis Vaccinations?

Since the vaccines were first developed, the hepatitis A and B vaccines have become part of the regular childhood immunization schedule. They are not considered a routine adult immunization.

"When we're talking about adults, I would say yes, get the vaccine if they fit into one of these risk factors" says Poland. "If they don't fit into the risk factors, their risk is so low that there's no compelling reason to do it."

People at risk for hepatitis A include:

Anyone traveling to or working in areas where hepatitis A is more widespread.

People whose work puts them in potential contact with hepatitis A, such as those who work with the hepatitis A virus in research labs

People who are treated with clotting-factor concentrates

People who have chronic liver disease

People who use recreational (street) drugs, injected or not

Men who have sex with men

People at risk for hepatitis B include:

Anyone traveling to or working in areas where hepatitis B is more widespread.

Health care workers and other people whose job exposes them to human blood